(a) Technical Field
The present disclosure relates to a method for manufacturing a wheel for a vehicle. More particularly, it relates to a method for manufacturing a metal/composite hybrid wheel for a vehicle by molding an inner rim of a composite material by compression and, at the same time, bonding an outer rim of a metal material to the inner rim to induce compressive residual stress in the bonding area by a difference in thermal expansion coefficient between the outer rim and the inner rim. The present methods provide an increase in the adhesive strength of the bonding area and the durability of the wheel. The present disclosure further relates to a wheel for a vehicle manufactured by the method, particularly a metal/composite hybrid wheel for a vehicle manufactured by the method.
(b) Background Art
In general, a wheel for a vehicle is connected to the center of a rubber tire in which air or nitrogen is filled and then firmly connected to the axle of the vehicle. An aluminum wheel, which has a good design, excellent cooling efficiency, and improved fuel efficiency due to a low weight, is widely used.
Recently, there has been an increased interest in a metal/composite hybrid wheel using a fiber-reinforced composite material having excellent mechanical properties. Such hybrid wheels have been manufactured by a vacuum bag molding (VBM) method or a resin transfer molding (RTM) method.
As shown in FIG. 1, the vacuum bag molding method includes inserting a material, such as prepreg, into a metal mold, mounting an intermediate mold inside the metal mold, applying a Teflon film onto the resulting mold, wrapping the resulting mold using a breeder, placing the resulting mold in a vacuum bag, absorbing air from the vacuum bag using a vacuum pump, and performing an autoclave molding process, to thus produce the product.
However, the process for manufacturing the product using the vacuum bag molding method is complicated, and expensive materials (such as Teflon film, breeder, etc.) are used. Thus, the vacuum bag molding method is unsuitable for mass production and increases the manufacturing cost.
As shown in FIG. 2, the resin transfer molding method includes disposing dry fiber and preform in a lower mold, connecting an upper mold to the lower mold, pressing or clamping the upper and lower molds, injecting a resin mixed with a catalyst into the resulting mold (e.g. using an RTM machine), curing the resin at room temperature or at a high temperature after the resin is impregnated, and removing the mold, to thus produce the product.
However, when the resin transfer molding method is used, pores are generated in the final product, which reduces the strength. Further, it is difficult to control the quality of the product due to the resulting presence of a resin rich area. As such, is it difficult to ensure uniform quality of the products using a resin transfer molding method.
Further, because both the vacuum bag molding method and the resin transfer molding method for manufacturing a hybrid wheel require various adhesion and bonding processes to integrally mold the outer rim of a metal material and the inner rim of a composite material, these manufacturing processes are very complicated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.